DESCRIPTION
Glycolic acid is an alpha-hydroxy acid (AHA) that is commonly derived from sugarcane, beets, or other fruits.
Glycolic acid is widely used in skincare products due to its exfoliating properties.
As a gentle chemical exfoliant, glycolic acid works by loosening dead skin cells on the surface of the skin, promoting cell turnover and revealing smoother, brighter skin.
Glycolic acid is also known for helping to improve the appearance of fine lines, hyperpigmentation, acne, and uneven skin tone.
Cas Number
79-14-1
SYNONYMS
Hydroxyacetic acid,2-Hydroxyethanoic acid, Alpha-hydroxyethanoic acid,Glycolic acid (HOCH2COOH)
Definition and Basic Chemical Properties:
Glycolic acid (HOCH₂COOH) is a naturally occurring alpha-hydroxy acid (AHA) that belongs to the group of carboxylic acids.
Glycolic acid is the smallest AHA and is commonly derived from natural sources like sugarcane, beets, and other fruits.
Its simplicity in structure, with just two carbon atoms, makes it a unique and effective compound for various applications.
In terms of its molecular structure, glycolic acid consists of a hydroxyl group (-OH) attached to the alpha carbon of an acetic acid molecule.
The presence of this hydroxyl group gives glycolic acid its exfoliating properties.
Historical Background and Discovery:
The discovery of glycolic acid dates back to the 19th century, with its first identification being credited to the French chemist Henri Braconnot in 1848.
Initially, it was extracted from natural sources, but its widespread use in dermatology and other industries came much later.
The acid gained significant attention in the 1970s when it was incorporated into cosmetic products, particularly for its ability to exfoliate skin and enhance cellular turnover.
Importance in Scientific Research and Industry:
Glycolic acid's ability to penetrate the skin barrier makes it one of the most effective AHAs used in both medical and cosmetic applications.
It plays a major role in the dermatological field, especially in the treatment of skin conditions such as acne, hyperpigmentation, and signs of aging.
Beyond skincare, glycolic acid is also widely used in industries like textiles, cleaning, and biodegradable plastic production.
Chemical Structure and Properties
Molecular Structure:
The molecular formula of glycolic acid is C₂H₄O₃.
It consists of two carbon atoms, four hydrogen atoms, and three oxygen atoms.
Its structure can be represented as HOCH₂COOH, where the hydroxyl group (-OH) is attached to the alpha carbon atom of the carboxylic acid group (-COOH).
This small size allows glycolic acid to penetrate the skin more easily than larger AHAs, contributing to its effectiveness as an exfoliator.
Functional Groups:
The key functional groups in glycolic acid are the hydroxyl group (-OH) and the carboxyl group (-COOH).
The hydroxyl group is responsible for the compound’s ability to dissolve in water, while the carboxyl group plays a critical role in its acidic properties.
Physical Properties:
Solubility: Glycolic acid is highly soluble in water, making it easy to formulate into liquid or gel-based products.
Melting Point: Its melting point is around 80°C (176°F), which is relatively low and contributes to its effectiveness in skin care formulations.
pH: Glycolic acid is a weak acid, and its solutions are acidic. The typical pH for glycolic acid products in cosmetics ranges between 3.0 to 4.0.
Chemical Reactivity:
As an AHA, glycolic acid has exfoliating properties due to its ability to break the bonds between dead skin cells, promoting cellular turnover.
The carboxyl group also allows it to participate in various chemical reactions, making it useful in manufacturing and synthesis.
Production of Glycolic Acid
Natural Sources:
Glycolic acid is naturally found in fruits like sugarcane, grapes, and beets.
It can also be produced by fermentation from natural sugars using certain microorganisms.
These natural sources have made glycolic acid a popular ingredient in natural skin care products, though synthetic production is more common for commercial applications.
Synthetic Production Methods:
Oxidation of Glycolaldehyde: One common method of producing glycolic acid involves the oxidation of glycolaldehyde (HOCH₂CHO), where the aldehyde group is converted into a carboxyl group.
This method is often used for large-scale industrial production.
Hydrolysis of Dichloroacetate: Another method involves the hydrolysis of dichloroacetate in the presence of an alkaline solution, which leads to the formation of glycolic acid.
Biotechnological Production:
In recent years, there has been a push towards sustainable methods of glycolic acid production, with biotechnology offering a greener alternative.
Fermentation techniques involve microorganisms, such as bacteria or yeast, which can convert plant-derived sugars into glycolic acid.
This method is seen as more environmentally friendly and sustainable compared to traditional chemical processes.
Commercial Scale Production and Challenges:
While glycolic acid is widely produced, scaling up production has its challenges.
Maintaining product purity, consistency, and the high cost of raw materials (like sugarcane) can influence the overall cost of glycolic acid production.
Additionally, ensuring a sustainable supply chain is important for both environmental and economic reasons.
Mechanisms of Action
Biological Mechanism in Skin Care:
When applied to the skin, glycolic acid penetrates the epidermis, breaking down the bonds between the outermost dead skin cells, promoting exfoliation.
By encouraging the shedding of old cells, glycolic acid accelerates the turnover rate, revealing fresh, new skin underneath.
This process also stimulates the production of collagen, which is essential for skin elasticity.
Cellular Interactions:
Glycolic acid acts primarily by interacting with the stratum corneum (the outermost layer of the skin).
It helps to soften the corneocytes (skin cells), making them less cohesive and thus easier to shed.
As the skin regenerates, the underlying layers of the skin become more hydrated and youthful in appearance.
Comparison with Other AHAs:
While glycolic acid is the most commonly used AHA, other acids like lactic acid, citric acid, and malic acid also offer exfoliating benefits.
However, glycolic acid’s smaller molecular size allows it to penetrate the skin more effectively, making it more potent than other AHAs for certain applications, like deep exfoliation.
Uses and Applications
In Dermatology and Skin Care:
Chemical Peels: Glycolic acid is commonly used in superficial chemical peels, which help treat skin conditions such as acne, hyperpigmentation, and fine lines.
The acid exfoliates the skin’s surface, removing dead skin cells and allowing new, healthier skin to emerge.
Anti-aging Properties: By stimulating collagen production, glycolic acid helps improve the skin’s texture and firmness, reducing the appearance of fine lines and wrinkles.
Acne Treatment: Glycolic acid helps prevent clogged pores, which are a major cause of acne.
It also has anti-inflammatory properties that reduce redness and swelling associated with acne breakouts.
In Industrial Applications:
Textile Industry: Glycolic acid is used in the textile industry to adjust the pH of dye baths and to help remove impurities from fabrics.
Leather Industry: It is used to treat leather, softening it and improving its texture.
Biodegradable Plastics: In recent years, glycolic acid has been explored for its use in producing biodegradable polymers like polyglycolic acid (PGA), which is used in eco-friendly packaging and medical sutures.
SAFETY INFORMATION ABOUT GLYCOLIC ACID
First aid measures:
Description of first aid measures:
General advice:
Consult a physician.
Show this safety data sheet to the doctor in attendance.
Move out of dangerous area:
If inhaled:
If breathed in, move person into fresh air.
If not breathing, give artificial respiration.
Consult a physician.
In case of skin contact:
Take off contaminated clothing and shoes immediately.
Wash off with soap and plenty of water.
Consult a physician.
In case of eye contact:
Rinse thoroughly with plenty of water for at least 15 minutes and consult a physician.
Continue rinsing eyes during transport to hospital.
If swallowed:
Do NOT induce vomiting.
Never give anything by mouth to an unconscious person.
Rinse mouth with water.
Consult a physician.
Firefighting measures:
Extinguishing media:
Suitable extinguishing media:
Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide.
Special hazards arising from the substance or mixture
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas
Advice for firefighters:
Wear self-contained breathing apparatus for firefighting if necessary.
Accidental release measures:
Personal precautions, protective equipment and emergency procedures
Use personal protective equipment.
Avoid breathing vapours, mist or gas.
Evacuate personnel to safe areas.
Environmental precautions:
Prevent further leakage or spillage if safe to do so.
Do not let product enter drains.
Discharge into the environment must be avoided.
Methods and materials for containment and cleaning up:
Soak up with inert absorbent material and dispose of as hazardous waste.
Keep in suitable, closed containers for disposal.
Handling and storage:
Precautions for safe handling:
Avoid inhalation of vapour or mist.
Conditions for safe storage, including any incompatibilities:
Keep container tightly closed in a dry and well-ventilated place.
Containers which are opened must be carefully resealed and kept upright to prevent leakage.
Storage class (TRGS 510): 8A: Combustible, corrosive hazardous materials
Exposure controls/personal protection:
Control parameters:
Components with workplace control parameters
Contains no substances with occupational exposure limit values.
Exposure controls:
Appropriate engineering controls:
Handle in accordance with good industrial hygiene and safety practice.
Wash hands before breaks and at the end of workday.
Personal protective equipment:
Eye/face protection:
Tightly fitting safety goggles.
Faceshield (8-inch minimum).
Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).
Skin protection:
Handle with gloves.
Gloves must be inspected prior to use.
Use proper glove
removal technique (without touching glove's outer surface) to avoid skin contact with this product.
Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices.
Wash and dry hands.
Full contact:
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
Splash contact
Material: Nitrile rubber
Minimum layer thickness: 0.11 mm
Break through time: 480 min
Material tested:Dermatril (KCL 740 / Aldrich Z677272, Size M)
It should not be construed as offering an approval for any specific use scenario.
Body Protection:
Complete suit protecting against chemicals, The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.
Respiratory protection:
Where risk assessment shows air-purifying respirators are appropriate use a fullface respirator with multi-purpose combination (US) or type ABEK (EN 14387) respirator cartridges as a backup to engineering controls.
If the respirator is the sole means of protection, use a full-face supplied air respirator.
Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).
Control of environmental exposure
Prevent further leakage or spillage if safe to do so.
Do not let product enter drains.
Discharge into the environment must be avoided.
Stability and reactivity:
Chemical stability:
Stable under recommended storage conditions.
Incompatible materials:
Strong oxidizing agents:
Hazardous decomposition products:
Hazardous decomposition products formed under fire conditions.
Carbon oxides, Nitrogen oxides (NOx), Hydrogen chloride gas.
Disposal considerations:
Waste treatment methods:
Product:
Offer surplus and non-recyclable solutions to a licensed disposal company.
Contact a licensed professional waste disposal service to dispose of this material.
Contaminated packaging:
Dispose of as unused product